The present disclosure relates to an image pickup element having a fixed charge film on a semiconductor substrate, a method of manufacturing such an image pickup element, and an electronic apparatus including such an image pickup element.
In a solid-state image pickup device (an image pickup device) such as a charge coupled device (CCD) image sensor and a complementary metal oxide semiconductor (CMOS) image sensor, a solid-state image pickup element (an image pickup element) including a photoelectric conversion section is disposed for each pixel. The photoelectric conversion section of the image pickup element may be configured of, for example, a semiconductor material such as silicon (Si). On a surface of the photoelectric conversion section, crystal defects and dangling bonds are present due to breaking of a crystal structure. The crystal defects and the dangling bonds lead to extinction, due to recombination of an electron-hole pair generated in the photoelectric conversion section, or lead to generation of a dark current.
For example, International Publication No. WO 2012/117931 discusses a solid-state image pickup device of a backside illumination type. In this solid-state image pickup device, in order to suppress generation of a dark current, an insulating film (a fixed charge film) having negative fixed charge on a light-receiving surface (a back surface) of a Si substrate is formed. In the Si substrate, a photodiode is embedded as a photoelectric conversion section. On a Si surface where the fixed charge film is formed, an inversion layer is formed. A Si interface is pinned by this inversion layer, which suppresses the generation of the dark current.
Further, in the Si substrate, a groove may be provided between pixels next to each other, and optical color mixture may be suppressed by filling this groove with an insulating film.